Method and system for injecting RF signal into a fluid-containing system

ABSTRACT

A method and system for injecting a pulsed radio frequency signal into a fluid-containing system in order to create and propagate an electromagnetic field throughout the fluid-containing system. Use electromagnetic field may be used to prevent the formation and build-up of scale in the fluid-containing system and/or to prevent the proliferation of bacteria within the fluid-containing system. The method and system may also be used to inject a pulsed radio frequency signal at a number of points in a fluid-containing system, or to inject a pulsed radio frequency signal to a number of independent fluid-containing systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. continuation patent application of,and claims priority under 35 U.S.C. §120 to, U.S. patent applicationSer. No. 13/035,419, filed Feb. 25, 2011, which '419 application isexpressly incorporated herein by reference, and which '419 applicationpublished as U.S. Patent Application Publication No. US 2012/0217815 A1on Aug. 30, 2012, which publication is likewise expressly incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to a method and a system fortreating a fluid-containing system in order to resist the formation andbuild-up of scale deposits.

Scale is the build-up of mineral salt deposits on internal surfaces offluid-containing equipment, such as pipes. In particular, calcium andmagnesium, which are commonly contained in water, are heavily involvedin the formation of scale.

Scale is formed when mineral ions present in a fluid reach conditions atwhich they change phases from liquid to solid. Ions present in a fluidrequire energy to begin the process of forming a solid. Formation of asolid on an existing surface, such as the internal surface of a pipe,requires less energy. Accordingly, it is on the surfaces of pipes andother equipment with which the fluid comes into contact that mineralions most frequently undergo their phase change to solids. The solidsform on, and adhere to, these surfaces, creating scale.

When scale builds up in a pipe or other conduit, it alters the flow ofthe fluid. By decreasing the volume of fluid that flows through a pipe,scale requires pumps and other industrial equipment to use more energyin order to transport the same volume of fluid. Scale may also increasepressure in a pipe, which can cause leaks and breakages. Because heatprovides energy to fuel the ions' phase change to solid, scale build-upon heated equipment, such as steam boilers and heat exchangers, isespecially problematic. Scale formation on these devices may lead toreduced heat transmission, higher fuel usage, and even local overheatingand failure. The build-up of scale also may have a number of indirecteffects, such as providing a location for bacteria to build up in thefluid-containing system and interacting with soap to prevent cleaning ofthe fluid-containing system.

A number of methods to resist scale formation and build-up are known inthe art. For instance, chemical solutions have been introduced intofluid-containing systems. The use of chemical solutions, however, isundesirable both because it requires constant replenishment and becauseit contaminates the fluid. Accordingly, a number of physical watertreatment methods have been identified. One physical water treatmentmethod involves positioning electrodes in the fluid-containing system.However, as the electrodes erode, they lose their effectiveness and needto be replaced. Another method involves the positioning of magnets indirect contact with the fluid. However, the magnets collect magneticdebris which, itself, can obstruct the pipe.

Another method of physical water treatment involves the creation of anelectromagnetic field, either exteriorly and/or interiorly of a pipingsystem. An electromagnetic signal prevents the formation and build-up ofscale by providing energy to the ions, causing them to undergo a phaseshift to a solid state within the fluid. Accordingly, the ions stick toeach other, rather than to the internal surfaces of pipes and otherequipment. As such, they continue to flow through the fluid-containingsystem and do not build up in the fluid-containing system.

This method of treatment is disclosed, for example, in U.S. Pat. No.5,514,283. There, an electromagnetic field is created in afluid-containing system in different ways. One method involves a primarywinding of electrical wire, to which an energizing means is connected,and a secondary winding of electrical wire. The primary and secondarywindings are separated by a ferrite core. The secondary winding has apair of terminals, which are placed in electrical contact with afluid-containing conduit at axially spaced-apart contact zones. Aconductive path extends along the conduit between the two contact zones,creating a low voltage, high current signal between the terminals. Thehigh current generates an electromagnetic field, that propagates alongthe conduit in both directions from the contact zones. In anothermethod, a ferrite core is coiled co-axially or spirally around theconduit in a manner so as to extend through a primary winding ofelectrical wire. In this method, the electromagnetic field is achievedby making the pipe itself and/or the fluid therein, serve as thesecondary winding.

In many applications of physical water treatment involving anelectromagnetic field, it is necessary to have the electromagnetic fieldfreely propagate throughout the fluid-containing system. However, thepropagation of an electromagnetic field across large distances in afluid-containing system has often been difficult and/or impossible toachieve with known methods and devices. For instance, pipingconfigurations in the fluid-containing system create hidden return pathswhich effectively force the electromagnetic field to a loop, leavingsignificant portions of the system untreated.

SUMMARY OF THE INVENTION

An embodiment of the present invention comprises a method and apparatusfor protecting a fluid-containing system from scale deposits. In thisembodiment a radio frequency signal is injected into a fluid-containingsystem in order to provide propagation of an electromagnetic signalthroughout the fluid-containing system. By operatively connecting oneterminal of a secondary coil of a transformer to the fluid-containingsystem and another terminal to ground, an embodiment of the presentinvention prevents the electromagnetic signal from becoming forced to aloop. The present invention thus provides an improved method andapparatus for protecting a fluid-containing system against the formationand build-up of scale.

In another embodiment of the present invention, a radio frequency signalis injected into a number of independent fluid-containing systems usinga single treatment device. Using known methods, one would be forced toseparately install an individual, treatment device on eachfluid-containing system to be treated. However, an embodiment of thepresent invention overcomes this disadvantage. By operably connectingone end of a secondary coil of the transformer to ground, the other endof the secondary coil may be split to provide a number of terminals.Each of these terminals may be operably connected to an individual load,each load comprising an independent fluid-containing system. Anembodiment of the present invention thus provides a method and apparatusfor protecting a number of fluid-containing systems against theformation and build-up of scale using a single treatment device.

In another embodiment of the present invention, a radio frequency signalis injected into a fluid-containing system in order to prevent theproliferation of bacteria. Although not being limited by any theory ofoperation, it is believed that the pulsed radio frequency signal servesto prevent the proliferation of bacteria by immobilizing existingbacteria in the fluid-containing system. Bacteria configure themselvesto a polarity that matches that of their surrounding environment. Thus,when their environment undergoes a change in polarity, the bacteriaundergo a corresponding change. By injecting a pulsed radio frequencysignal into a fluid-containing system, the polarity of the bacteria'senvironment is brought into a constant state of flux. It is believedthat the bacteria cannot keep up with the changes in the polarity oftheir environment, and become immobilized. The validity and scope ofthis embodiment of the invention, however, are not limited by anyparticular theory of operation.

BRIEF DESCRIPTION OF THE DRAWINGS

A clear conception of the advantages and features of one or moreembodiments will become more readily apparent by reference to theexemplary, and therefore non-limiting, embodiments illustrated in thedrawings:

FIG. 1 is an electronic circuit diagram of an embodiment of the presentinvention operably connected to a fluid-containing conduit.

FIG. 2 is an electronic circuit diagram of an embodiment of the presentinvention operably connected to a number of fluid-containing conduits.

FIG. 3 is an electronic circuit diagram of a system for generating andinjecting a pulsed radio frequency signal into a fluid-containing systemin accordance with an embodiment of the present invention.

FIG. 4 is an electronic circuit diagram of a system for generating andinjecting a pulsed radio frequency signal into a fluid-containing systemin accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The formation and build-up of scale is a problem that affects manyindustries. An embodiment of the present invention provides safe andefficient fluid treatment and can easily be installed to anyfluid-containing system. An embodiment of the present invention may beparticularly useful in treating, for example, cooling towers, oil andnatural gas wells, geothermal wells, boilers, and any other heatexchangers that utilize fluids or fluid containing piping systems wherescaling occurs. Moreover, an embodiment of the present invention may beused to prevent the proliferation of bacteria in fluid-containingsystems, for example, pools and spas, beer lines, cooling towers,dairies, sea water cooling systems, or any other fluid containing pipingsystem where bio-fouling occurs.

According to the present invention, a pulsed radio frequency signal, isinjected to a fluid-containing system. By injecting a pulsed radiofrequency signal into a fluid-containing system, an embodiment of theinvention propagates an electromagnetic field throughout thefluid-containing system. Therefore, an embodiment of the presentinvention provides physical water treatment without the need forchemicals, electrodes, magnets or other descaling devices mounted withinthe fluid-containing system. Additionally, an embodiment of the presentinvention operates on little energy and requires little to no on-goingmaintenance.

In order to obtain a propagation of the electromagnetic field throughoutthe system, the signal preferably has the characteristics of anoscillating, exponentially decaying waveform. The frequency of thesignal can be selected to achieve a desired propagation for a particularfluid-containing system. Preferably the frequency of the signal isselected to be between about 100 and 200 KHz. More preferably, thefrequency of the signal is selected to be between about 120 and 180 kHz.

The signal is created in bursts, or pulses, which are preferablyrepeated at variable, pseudo-random intervals. Each pulse preferably hasa frequency between 5 KHz and 20 KHz. Accordingly, in a preferredembodiment, the pulses are repeated between 5,000 and 20,000 times persecond.

An embodiment of the invention is illustrated in FIG. 1. In thisembodiment, a pulsed radio frequency signal, as described above, isintroduced in the primary coils 3 of a transformer 1. The transformer 1transfers the signal to the secondary coils 3. The signal is theninjected into a fluid-containing system 7 by a connection between thesystem and a first terminal of a secondary coil of the transformer 9.Because the fluid-containing system acts as a load, this terminal 9 mayalso be referred to as a load terminal. In order to provide a lowimpedance to balance the load presented by the fluid-containing system7, a second terminal of the secondary coil 11 is operably connected toground. Accordingly, this terminal 11 may be referred to as a groundterminal.

In a preferred embodiment, the transformer 1 is a toroidal transformer,having a core 17 that comprises a ferrite ring. This type of transformer1 operates particularly well at high frequencies. Preferably, at leastthe secondary coil 5 of the toroidal transformer 1 is formed by wrappinga number of turns of electrical wire around the ferrite ring core 17. Byusing wire as the secondary coil 5 of the transformer, the treatmentdevice of the preferred embodiment may be operably connected to afluid-containing system with ease. Where the secondary coil 5 is formedin this way, the load terminal 9 and the ground terminal 11 arepreferably located at opposite ends of the wire that forms the secondarycoil 5. Alternatively, a standard transformer unit may be used. In thatcase, a load terminal 9 may be connected, via electrical wire, to onetap of the secondary coil 5 and a ground terminal 11 may be connected,via electrical wire, to another tap of the secondary coil. The number ofturns of secondary coil 5 between the two taps may be selected toachieve a signal having desired properties.

The transformer may have a varying number of turns of primary coil 3 andsecondary coil 5. Generally, few turns of both primary coil andsecondary coil are needed. By selecting a particular ratio of turns, onemay either increase or decrease the voltage that is used in treating thefluid-containing system 7.

In an embodiment of the invention, a load terminal 9 of the secondarycoil 5 is connected to a pipe or other conduit 13 through which a fluidflows. Preferably, the conduit 13 is made of conductive material, inwhich case a load terminal 9 may be operably connected to thefluid-containing system 7 by contact between the terminal and theconduit. In other embodiments, however, the conduit 13 may be made of anon-conductive material. Where the conduit 13 is non-conductive, a loadterminal 9 may be operatively connected to the fluid-containing system 7in a number of ways. For example, a conductive material may be insertedto a section of the conduit 13, and a load, terminal 9 brought intocontact with the conductive insert. Alternatively, a conductive materialmay be clamped around a section of the conduit 13 and a load terminal 9brought into contact with the conductive material, allowing injection ofthe signal by capacitance.

The ground terminal 11 is operably connected to ground to form a currentreturn path from one side of the secondary coil 5 to the other. The loadterminal 9 is operably connected to the fluid-containing system 7, whichis, itself, coupled to ground. Accordingly, so as not to provide aspecific point for the return path and thereby reduce the potentialpropagation of the signal, the ground terminal 11 is operably connectedto ground through a capacitor 15.

In an embodiment of the present invention, a single treatment device isused to treat multiple fluid-containing systems. This embodiment isillustrated in FIG. 2. Here, the electrical wire at one end 19 of asecondary coil 5 of a transformer is split to provide multiple loadterminals 9. Each load terminal 9 is operably connected to anindependent fluid-containing system 7 to provide the desired treatment.

The radio frequency signal may be generated and introduced in theprimary coils of a transformer in a number of ways. In one preferredembodiment, a microcontroller having a digital to analogue converterdirectly synthesizes the signal as a pulsed waveform having the desiredcharacteristics. The signal is then amplified, if necessary, and fed tothe primary coil of the transformer. The signal is injected into thefluid-containing system, as described above.

An example of this embodiment is illustrated in FIG. 3. Amicrocontroller equipped with a digital to analogue converter (DAC) 19generates, at three volts, a signal 21, which comprises an oscillatingwaveform having a desired frequency and which is pulsed pseudo-randomly.The signal 21 is then shifted and amplified up to twelve volts by apreamplifier 23 and fed to a power amplifier 25, which raises thecurrent of signal so that it can drive a high-frequency transformer 1.The resulting signal 27 is introduced to the primary coils 3 of thehigh-frequency transformer 1. The signal is injected into thefluid-containing system 7 as described above.

In another preferred embodiment, a microcontroller produces shorthigh-current pulses. The short high-current pulses are then shifted andamplified, if necessary, before being switched into a series resonant LCcircuit. The LC circuit comprises a high-voltage capacitor and theprimary coils of a transformer, which act as the inductor. When chargedby the pulse, the LC circuit generates an oscillating waveform having aparticular frequency. By selecting the values of inductance (L) andcapacitance (C), a user may preselect a frequency that is optimized fortreatment of the particular fluid-containing system. The signal isinjected into the fluid-containing system as described above.

An example of this embodiment is illustrated in FIG. 4. Amicrocontroller 29 generates, at three volts, short high-current pulses31 at a frequency that ranges pseudo-randomly between 5 and 20 KHz. Thepulses 31 are then shifted up to twelve volts and the current isamplified by a circuit control processor 33. The amplified pulses 35 arefed to the base of a bipolar transistor 37, where they are switched intoa series resonant LC circuit 39, comprising a capacitor 41 and theprimary coils 3 of a high-frequency transformer 1. The values ofinductance (L) and capacitance (C) are selected to produce anoscillating waveform having a frequency between 100 and 200 KHz.Accordingly, a signal 43, which comprises an oscillating waveform with afrequency between 100 and 200 KHz, and that is pulsed pseudo-randomlybetween the ranges of 5 to 20 KHz, is introduced in the primary coils 3of a transformer 1. The signal is injected into the fluid-containingsystem 7 as described above.

It can be seen that the described embodiments provide a unique and novelmethod and system for injecting a radio frequency signal into afluid-containing system that has a number of advantages over those inthe art. While there is shown and described herein certain specificstructures embodying the invention, it will be manifest to those skilledin the art that various modifications and rearrangements of the partsmay be made without departing from the spirit and scope of theunderlying inventive concept and that the same is not limited to theparticular forms herein shown and described except insofar as indicatedby the scope of the appended claims.

What is claimed is:
 1. A system of treating fluid-containing equipmentin order to resist the formation and build-up of scale deposits, thesystem being arranged to inject a radio frequency signal into thefluid-containing equipment, and the system comprising a conduit,containing a fluid, and a transformer comprising a primary coil and asecondary coil, the secondary coil having a first terminal operablyconnected to the conduit to inject the signal into the fluid-containingequipment and a second terminal operably connected to ground to balancethe load presented by the fluid-containing equipment, and wherein, inuse, the system causes propagation of an electromagnetic signal in theconduit.
 2. The system of claim 1, wherein the transformer is a toroidaltransformer, having a ferrite ring core.
 3. The system of claim 2,wherein the secondary coil is formed by wrapping a number of turns ofcable around the core.
 4. The system of claim 1, wherein the conduit ismade of conductive material and the first terminal of the secondary coilis operably connected to the conduit through contact with the conduit.5. The system of claim 1, wherein the conduit is non-conductive andcontains a conductive material inserted to a section of the conduit, thefirst terminal of the secondary coil being operatively connected to theconductive material.
 6. The system of claim 1, wherein the conduit isnon-conductive and contains a conductive material clamped around asection of the conduit, the first terminal of the secondary coil beingoperatively connected to the conductive material.
 7. The system of claim1, wherein the second terminal of the secondary coil is operablyconnected to ground through a capacitor.
 8. The system of claim 1,further comprising a signal generator operable to generate a pulsedradio frequency signal; the primary coil of the transformer beingoperably connected to the signal generator to receive the pulsed radiofrequency signal.
 9. The system of claim 8, wherein the signal generatorcomprises a microcontroller operable to generate a pulsed radiofrequency signal, a pre-amplifier operable to shift the signal, and anamplifier operable to amplify the signal.
 10. The system of claim 1,further comprising a microcontroller operable to produce a pulsedcurrent, a series LC circuit in which the primary coil of thetransformer acts as an inductor, and a transistor operable to switch thepulsed current into the series LC circuit.
 11. A fluid treatment devicefor resisting the formation and build-up of scale deposits, the devicebeing arranged to inject a radio frequency signal into a conduit of afluid-containing system containing a fluid, and the device comprising atransformer comprising a primary coil and a secondary coil, thesecondary coil having a first terminal for operative connection to theconduit to inject the signal into the fluid-containing system and asecond terminal operably connected to ground arranged to balance theload presented by the fluid-containing system, and wherein, in use, thedevice causes propagation of an electromagnetic signal in the conduit.12. A system of treating equipment containing water-based fluid in orderto resist the formation and build-up of scale deposits, the system beingarranged to inject a radio frequency signal into the fluid-containingequipment, and the system comprising a conduit, containing a water-basedfluid, and a transformer comprising a primary coil and a secondary coil,the secondary coil having a first terminal operatively connected to theconduit to inject the signal into the fluid-containing equipment and asecond terminal operably connected to ground to balance the loadpresented by the fluid-containing equipment, and wherein, in use, thesystem causes propagation of an electromagnetic signal in the conduit.